A thermal anemometer measures fluid velocity using heat transfer phenomena. Thermal anemometer micro-flow sensors typically contain identical upstream and downstream temperature-sensitive elements and a heater located between them. The layout of such a sensor is usually symmetrical, including spatial positioning of all functional elements and distribution of their electrical parameters. In theory, this symmetry provides zero offset of the sensor and a symmetrical response on bidirectional input signals. However in practice, variations in physical parameters inevitably occur during the manufacturing process and cause non-zero offsets of the sensor. This offset as well as temperature drifts and long-term drift caused by temperature and time instability of the materials of the sensor may seriously affect the accuracy of measurements taken using the flow sensing devices. Non-zero offsets must be compensated in the majority of applications to provide a required level of sensor accuracy.